The two main types of cameras used in security systems are Analog CCTV systems and IP camera systems. CCTV stands for ‘closed circuit television’ and IP stands for ‘internet protocol.’ HD and megapixel network cameras have an important role to play in video surveillance applications. They can provide images that are more useful, with more image detail and with wider coverage than standard resolution cameras. Here we review some of the main differences between these two types of cameras.
The primary difference between IP and Analog cameras is in how they function. Basically, a closed circuit camera is designed to send video and audio signal waves through a closed circuit that can only be seen on one monitor or collection of monitors at a single location. The quality of the video recording degrades quickly the further the object moves from the camera. On the other hand, an IP camera is capable of sending and receiving digital data over the internet or a computer network. Most of the cameras that are able to perform this function are known as mega pixel or high definition cameras in the surveillance industry.
In places where the aim is to obtain a general overview of a scene not just the small part of a place it is better to use IP cameras because IP cameras usually provide HD, Full-HD or mega-pixel video footage for monitoring a larger field of view. In a shopping mall, for instance, your primary goal of camera installation may be to watch for the people and view their movements in a very large area. Also, when you want to have the whole scene of a parking lot not just small part of it and monitor the whole area, an IP camera with a large field of view and high details can be far superior to an analog camera with a small field of view and low resolution video output.
There are some situations where you need to be able to identify persons or objects in a scene. This could be point-of-sales monitoring where it is necessary to clearly see every item a customer is purchasing or situations where you need to be able to identify a face or read license plates of the high speed vehicles. Using the IP network cameras in all such cases will provide even higher resolution images with more details than analog ones. The latest IP cameras have the very nice capability of providing much better resolution than the old analog cameras. You can select cameras with 640 x 480 (VGA) lines to 2592 x 1944 pixels (5 megapixels). The resolution of the camera starts with the sensor, but also includes the lens and quality of the processor and compression used in the camera. To determine what resolution you need, you first consider how wide an area you would like to view and then what detail you need in that field of view. For example, suppose you want to view a doorway and you want to be able to identify a person’s face that comes in the door. In this case you only require a 640 x 480 resolution camera. On the other hand, suppose you want to be able to identify a license plate number in a parking lot that’s 60 feet wide. In this case you need a lot more pixels, and will require a higher Megapixel camera.